What was the most important invention of the past two thousand years?

Related Content:

News From:

This special feature marks the first collaboration between FEED and Edge, John Brockman's invitation-only Internet forum, where hundreds of the world's leading scientists and thinkers share their thoughts on issues ranging from the meaning of numbers to genetics to affirmative action. Readers can visit the Edge site for even more nominations, and an post their own suggestions in the Loop. — The Editors